1. Field of the Invention
The present invention relates to coordinate input devices used in electronic apparatuses such as computers, mobile phones or game devices for moving a cursor or a character, selecting a function, etc., on a display, and also relates to electronic apparatuses including the coordinate input devices.
2. Description of the Related Art
FIG. 15 is a perspective view of a notebook personal computer having a coordinate input device called a touch pad in front of a keyboard. This computer 200 includes a main body 201 and a display 203 which is connected to the main body 201 by a hinge at the rear end of the main body 201. A keyboard 204, a touch pad (coordinate input device) 205, and operation buttons 206 are provided on the top surface of the main body 201. The touch pad 205 has a flat, rectangular shape and is disposed in front of the keyboard 204, and the operation buttons 206 are disposed in front of the touch pad 205. The touch pad 205 is constructed such that a cursor, etc., that could be seen on the display 203 can be operated by sliding an operating member, for example, a finger, on the touch pad 205.
By using the above-described touch pad 205, a coordinate input operation, for example, an operation of moving a cursor., can be performed without moving one's hands from their home positions on the keyboard 204. In addition, since the touch pad 205 is flat, a thin, space saving computer can be obtained.
However, when the above-described flat touch pad 205 is used, since the coordinate input operation is performed by moving a finger on the touch pad 205, there is a problem in that it is difficult for the user to feel the sense of cursor movement compared to when other input devices such as computer mice are used, and a satisfactory operational feel cannot be obtained.
On the other hand, other notebook personal computers having rotating ball devices (trackball devices) instead of the touch pad 205 shown in FIG. 15 are also known. In such computers, the curser is moved by rotating a ball contained in the rotating ball device. Accordingly, the user can easily obtain the sense of cursor movement by feeling the rotation of the ball with his or her finger, so that the coordinate input operation can be easily performed. However, in order to install the rotating ball device in the computer, a space corresponding to the diameter of the ball must be provided inside the main body of the computer. Therefore, there is a problem that it is difficult to reduce the thickness of the computer.